Closure cap, method of making same, and sealed package therefor



E.STOVER Oct. 24, 1961 CLOSURE CAP, METHOD OF MAKING SAME, AND SEALED PACKAGE THEREFOR Filed March 11, 1958 United States Patent 3,005,563 CLOSURE CAP, METHOD 6F MAKING SAME, AND SEALED PACKAGE THEREFGR Harry E. Stover, Lancaster, Ohio, assignor to Anchor Hocking Glass Corporation, Lancaster, Ohio, a corporation of Delaware Filed Mar. 11, 1958, Ser. No. 720,775 Claims. (Cl. 215-40) The present invention relates to the sealing art and is an improvement over the closure and package shown in Holland Patent No. 1,909,406 dated May 16, 1933 and in the Stover Patent No. 2,670,868 dated March 3, 1954 and more particularly relates to a closure for making a hermetic seal on a glass container, to the sealed package formed thereby and to the method of making the closure.

The present invention is directed to a type of closure which is adapted to hermetically seal a glass container by being forced downwardly onto the mouth of the container in such a fashion as to compress a resilient gasket against a peripheral sealing surface on the glass container.

In the packaging of various commodities which are generally dispensed from the original receptacles, such as baby foods, it is important that the package be hermetically sealed in the first instance so that the contents will be properly preserved against contamination and fermentation and that the package be susceptible to effective re-sealing with ease to prevent evaporation, leakage or spoilage after it has been opened initially.

Also it is important that the package be of such a character that the user may easily remove and replace the closure cap and that the replaced closure effectively cover the mouth of the receptacle and stay in place with sufficient security to permit the package to be handled free- 1y. It is common knowledge that little care is exercised by users in replacing the closure cap after removing some of the contents of the package and that if the operation of putting the closure back on the container requires substantial effort or care, it is usually left oil. or applied improperly and insecurely.

Another problem with this type of closure has been that the raw edge of the closure cap becomes rusted and particles of rust may fall into the contents of the package. Also small strips of the coating may peel off and fall into the contents. The consumer considers these unsanitary foreign matter.

In addition, the closure must be inexpensive. A small saving on each closure is a great advantage because of the large quantities used. This means that the cost of materials used to make the closure must be kept at a minimum and the method of making the closure must be relatively inexpensive.

The type of closures in the Holland and Stover patents above have been sold in large quantities over a period of some years and have enjoyed a wide reception. The present invention is an improvement upon this type of closure and package and provides a better closure at a lower cost. Each alone would be an achievement in this highly competitive field. The two combined are the answer to a prayer.

The present invention minimizes or eliminates the above defects and has for one of its objects the provision of an improved closure cap which may be easily removed and re-applied without the use of special tools.

Another object of the present invention is the provision of a closure cap which utilizes a thin, short and inexpensive gasket to thereby reduce the cost of the cap without impairing its effectiveness.

Another object of the present invention is the provision of a closure cap in which the gasket is readily and easily applied thereto.

easily re-applied to form a secure seal on reapplication.

Another object of the present invention is the provision of an improved method of making a closure cap.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodi- =ment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a fragmentary sectional view of a cap blank showing the first step in the improved method of making the cap;

FIG. 2 is a sectional view similar to FIG. 1 showing the second step in the method of making the cap which comprises the coaxing-in of the raw edge of the skirt;

FIG. 3 is a sectional view which shows the third step in the method of making the cap which comprises curling the raw edge of the skirt inwardly to form a bead;

FIG. 4 is a sectional view showing the fourth step in the method of making the cap which comprises the application of the gasket;

FIG. 5 is a sectional view of the cap and finish prior to the application of the cap to the glass container; and

FIG. 6 shows the position of the cap after it has been applied to the container to form a hermetically sealed package.

Referring more particularly to FIGS. 1 through 4 which show the method of making the closure cap of the present invention, the first step is to stamp out a cup shaped blank shown in FIG. 1 from a sheet of tin plate which is preferably coated 0r lacquered. The blank comprises a cover portion 2 and a depending skirt portion 3. A shoulder 4 is formed in the skirt portion 3 to form an annular enlargement which will serve as a gasket-receiving channel, as will be later described. The upper part of the skirt portion 3 is formed with an inwardly flared portion 5 inclined to about 13 from the vertical to act as a wedge for the gasket when the cap is applied to the container, as will be more fully described below.

The second step of the method of forming the cap cornprises the coaxing inwardly of the raw edge 6 of the skirt portion 3, as shown in FIG. 2. This step of coaxing inwardly facilitates the curling inwardly of the raw edge of the skirt to form a hollow bead 7, which is the third step in the method and is shown in FIG. 3 of the drawings.

The head 7 is curled inwardly sufficiently to hide the raw edge 6 of the skirt portion 3 so that any rust forming on the raw edge 6 or any strips of coating which may peel off will fall into the hollow of head 7 and will not fall into the contents of the package. In addition,

the bead 7 underlies the upper shoulder 4 of the skirt portion to form the bottom of a gasket-receiving channel 8 (FIGS. 3 and 4) produced thereby and to act as a ledge upon which a gasket may rest; in addition, it improves the seal by stiffening the skirt.

The fourth step in the method of making the closure cap is the insertion of a ring gasket 9 in the gasket- '3 receiving channel 8, as shown in FIG. 4. Preferably, the ring gasket 9 is made of resilient rubber which may be a composition of natural rubber, synthetic rubber, or both. It will be noted that the gasketis resting on the inwardly rolled bead '7 and is spaced from the top shoulder 4 of the gasket-receiving channel 8.

The gasket 9 is relatively thin and short to permit the use of a high quality composition and savings in the cost of the rubber. The gasket is preferably about .075" thick and about .085" high as compared to prior similar type gaskets of about ..09" thick and .11." high heretofore required for the sealing operation. The savings made possible by the use of the gasket of the present invention are substantial, since large quantities of the closures are sold yearly. At the same time an improved seal is provided.

It will also be noted that the gasket can be easily inserted in the gasket-receiving channel 8 of the skirt without the use of special tools and that the gasket lie's' freely in the gasket-receiving channel 8 without being held by the inturned raw edge of the head 7, The limited free movement of the gasket improves the seal. In addition, the cost of manufacture is less where the lower edge of the gasket is not locked in position.

Referring more particularly to FIGS. 5 and 6 a container finish is shown having; a peripheral head 11 to act as a stop for the cap and an inclined sealing surface 12 directly below the bead 11 to cooperate with the gasket 9 of the cap to form a hermetic side seal therewith. The incline of the sealing surface 12 preferably does not extend beyond the bead 11.

FIG. 5 shows the cap 1 before it is applied to the container finish 10. When the cap. 1 is pressed onto the finish 10 as shown in FIG. 6, the rubber of the gasket 9 will be wedged or compressed between the inward flare 5 in the skirt portion 3 and the inclined sealing surface 12 of the container finish 10 thereby elfectuating a secure hermetic side seal and minimizing the thickness of rubber required therefor.

The exact position of the gasket depends on the relative pressures on the inside and outside of the jar during processing, the lubricant used on the gasket and the distance down on the glass finish to which it was forced during application. In some cases the inner side of the gasket is drawn upward, as shown in FIG. 6. In other cases the other side or the entire gasket may be drawn upward from the position shown in FIG. 6. The head 11 above the sealing surface 12 will act as a stop for the gasket 9 and prevent the cap from being blown off by pressure formed within the container when the container is placed in a retort and heated for sterilization purposes.

The coaction between the inclined sealing surface 12 of the container finish 10 and the gasket 9 permits the gasket 9 to be thinner and shorter than has been presently the case, thereby obtaining a substantial saving in the amount of rubber used. The wedge formed by the inwardly flared surface 5 of. the skirt portion 3 of the cap 1 increases the effectiveness of the sealing surface 12. The. two cooperate to provide an improved seal with a very thin gasket.

With this arrangement the closure cap 1 can be easily removed from the container.. The inclined sealing surface 12 narrows in'an upward direction which facilitates the initial upward movement of the cap while the bead 11 protrudes outwardly suificiently to permit the gasket 9 to be compressed when moving over it but does not protrude sufliciently to prevent its removal. This ease in cap removal permitted by the present invention is illustrated by the fact that about nine inch-torque-pounds is required to remove the cap as compared to greater inch-torque-pounds required to remove a closure such as shown in the Stov'er Patent No. 2,670,868. When the cap is to be replaced, it may be pressed onto the container so that the gasket 9 flexes over the slightly protruding head 11 and thereafter seats on the inclined sealing sur- 4 face 12 of the container finish in a compressed condition between the sealing surface 12 and the inwardly flared portion 5 of the skirt portion 3, as shown in FIG. 6. Here again the cap of the present invention requires about 18 inch-torque-pounds to replace as compared to the 83 inch-torque-pounds necessary in closures such as shown in Stover Patent No. 2,670,868.

It will be seen from the above that the present inven tion provides an improved closure cap and an improved seal at a lower cost.

The saving in material is substantial without impairment of the seal; on the contrary, an improved hermetic seal results. The cap may be more easily removed and rescaled, which is much desired by housewives who complain bitterly when a closure is difiicult to remove. The beaded edge prevents rust and stiifens the lower edge of the closure to effectively seal the closure and to permit the use of a thin gasket. The reinforced, stiffened bottom cooperates with the closure and glass sealing surfaces to form a secure seal with a thin, narrow gasket. The limited free vertical movement of the gasket with respect to the closure provides a better seal since the gasket may find its best sealing position with respect to the glass finish. In addition, cost of manufacture is less where the gasket is not anchored in position. The present invention provides an improved seal at a lower cost.

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. A sealed package comprising the combination of a container, the finish of said container having an inclined sealing surface and a bead above said sealing surface, and a closure cap having a cover portion and a depending skirt, said skirt having an outwardly extending portion to form a gasket-receiving channel and an inturned edge, the lower'portion of said gasket-receiving channel being substantially in a vertical plane and the upper portion of said gasket-receiving channel being tapered inwardly, an annular gasket freely mounted in said gasket-receiving channel resting on said inturned edge and spaced from the top of the gasketreceiving channel, said gasket being adapted to bear against and cooperate with the inclined sealing surface below said bead and be wedged between the inwardly flared surface of the cap and the inclined sealing surface of the finish to form an hermetic seal with the sealing surface.

2. A closure cap having a cover portion and a depending skirt portion, said skirt portion having an annular enlargement to form a gasket-receiving channel, the edge of said skirt portion being curled inwardly to form a bead,

an annular gasket freely mounted within said gasketskirt portion being curled inwardly to form a head, the

lower portion of the gasket-receiving channel being in a substantially vertical plane and the upper portion there-' of being inwardly tapered at about 13 to the vertical to act as a wedge for the gasket, an annular gasket freely mounted within said gasket-receiving channel and resting on said bead, said gasket being substantially .075

inch in height and being spaced from the top of said gas ket-receiving channel.

4. A closure cap having a cover portion and a depending skirt portion, said skiit portion having an annu fit largement to form a gasket-receiving channel, the

edge of said skirt being curled inwardly to form a bead, an annular gasket freely mounted Within said gasketreceiving channel and resting on said bead, the height of said annular gasket being less than the inner height of said gasket-receiving channel, and the lower portion of said gasket-receiving channel being substantially in a vertical plane and the upper portion of said gasket-receiving channel being tapered inwardly to form a wedge for the gasket.

5. A sealed package comprising the combination of a container having a finish with an inclined sealing surface and a closure cap having a cover portion and a depending ski-rt having a gasket-receiving channel, said skirt having an inwardly curled bead and a gasket freely positioned in said gasket-receiving channel and resting on said bead, the height of said annular gasket being less than the inner height of said gasket-receiving channel, the inner surface of said gasket adapted to bear against and cooperate with the inclined sealing surface of said container to form an hermetic side seal therewith, the lower portion of said gasket-receiving channel being substantial-ly in a vertical plane and the upper portion of said gasket-receiving channel being tapered inwardly to compress said gasket between the inwardly tapered surface of the cap and the inclined sealing surface.

References (Iited in the file of this patent UNITED STATES PATENTS 1,989,428 Scofield Jan. 29, 1935 2,079,813 Podel May 11, 1937 2,200,081 Gibbs May 7, 1940 2,308,126 Stover et a1. Ian. 12, 1943 2,444,506 Hammer July 6, 1948 2,544,969 Underwood Mar. 13, 1951 2,633,262 Acton Mar. 31, 1953 2,733,827 Foye Feb. 7, 1956 2,748,970 Chaplin June 5, 1956 2,772,013 Stover Nov. 27, 1956 FOREIGN PATENTS 535,929 Italy Nov. 19, 1955 

